This invention relates generally to copying machines and particularly to apparatus for collecting in an inverted orientation relatively large copy sheets discharged from a whiteprint, blueprint or similar copying machine.
It is widely known to provide stacking devices or trays at the exit ends of copying machines for collecting copy sheets and neatly stacking the sheets for removal from the machine. It also is known to provide such stacking devices with means for inverting or reversing the orientation of the sheets exiting from the machine so that the sheets are in sequential order, normally with the printed side down. However, such inverting devices normally have been designed for relatively small copy sheets and often rely upon the inherent stiffness of the sheets to facilitate the inverting process. For instance, U.S. Pat. No. 4,300,757, dated Nov. 17, 1981, discloses an apparatus for facially reversing or overturning copy sheets as they exit from a copying machine. In that patent, the copy sheets issue from the machine and seriatim strike a guide which deflects the sheets into a stacking tray where the sheets fall printed-side down into the tray. As with most such devices, the inherent stiffness of the relatively small copy sheets is utilized to advantage in the deflecting and stacking process.
Reverse stacking devices as described above are not applicable for use with whiteprint, blueprint or similar copying machines which handle relatively large copy sheets. For instance, such machines often use the diazo process where a translucent original is placed upon a relatively large sheet of sensitized diazo coated copy paper and the two sheets are fed together through the machine. The sheets are carried around a transparent cylinder which contains an ultraviolet lamp. Wherever the light passes through the original to the copy the sensitized coating on the copy is decomposed leaving the copy paper white. Wherever the image on the original shields the copy paper from the light the sensitized coating will remain as a latent image. After being separated from the original, the exposed copy paper passes into a developer section where ammonia vapors combine with the diazo coating in the latent image to form a highly legible permanent image on a clear white background. The copy then emerges from the machine as a flat, dry print ready for immediate use. This is but one type of copying machine with which the present invention is applicable, in that the size of the copy sheets may be as large as 36 x 42 inches.
It is readily apparent that because of the large size sheets used in whiteprint and blueprint copying machines, most known inverting or reversing stacking devices cannot be employed because of the lack of inherent stiffness in the large size copy sheets. In essence, the large sheets are somewhat "limp" as they emerge from the copying machine.
There is a definite need for a simple apparatus for collecting and inverting the orientation of large copy sheets discharged from a whiteprint, blueprint or similar copying machine. The present invention is directed to fulfilling this need.